U.S. Pat. No. 3,915,907, discloses that N-chlorothio-sulfonamides are particularly useful as a rubber additive. Since the issuance of U.S. Pat. No. 3,915,907, the demand for N-chlorothio-sulfonamides has been increasing and extensive research has been conducted to find an economical method of producing N-chlorothiosulfonamides.
West German Patent 1,101,407 discloses a method for the preparation of N-chlorothio-sulfonamides from N,N'-dithiobis(sulfonamides). The method of West German Patent No. 1,101,407 involves reacting the N,N'-dithiobis(sulfonamide) with chlorine in the presence of an organic inert solvent such as carbon tetrachloride or chloroform. Unfortunately, the prior art method suffers from many disadvantages.
One of the disadvantages is the solvent stripping operations are slow and involve up to 6 hours total batch time. To prevent the thermal degradation of the end product, low temperatures are required for stripping. The slow procedure contributes to the expense of the process. Another major disadvantage is the suspected carcinogenic nature of many chlorinated organic solvents.
In view of the ever increasing demand for chlorothio-sulfonamides and the dangers in preparing these compounds, there is a need for a safer and more efficient method for the preparation of these compounds.